Inorganic Chemistry, Vol. 12, No. 9,1973 2209
Notes contains SnC13-. A donor-adduct complex of SnC14, ((IScyclooctadiene)RhC1)2~2SnC14,has been prepared and found to have a strong v(Sn-C1) band at 313 cm-' (Nujol There is precedence for the reaction between I and Cl-, eq 6, if it is assumed that the donor-adduct isomer is the reactive f ~ r m . ~ ~ ' Although ~~'' an oxidative addition isomer is not expected to react with C1-, it will participate in the net reaction if it is in rapid equilibrium with a reactive, donoradduct isomer. The evidence for a rapid interconversion between isomers had been given above. It should also be noted that if less than stoichiometric amounts of C1- are added to solutions of I in dichloromethane, v(C0) for trans-IrCl(C0)(PPh3)2 appears and the intensities of both v(C0) bands for I decrease. The structural details of the donor-adduct isomer may resemble the simple metal-metal interaction found in ( h S CSHS)(CO)2Co*HgC12 or the halide-bridged structure found, for example, in19 c1 / \
Unfortunately, we have been unable to grow suitable crystals for an X-ray diffraction study. Discussion of the Isomerism. Kinetic20i21and synthetic5,22,23 evidence is available which indicates that reactions between metal complexes and HgXz or SnX4 may proceed in a stepwise fashion, with the first step involving donoradduct formation and the second, oxidation, e.g., eq 8.24 In
+ SnC1,
--f
(hS-C,H,)(CO),Rh(SnC1,) CO
(h5-C,H5)(CO)ClRh(SnCl,)
Uknowledgments. Acknowledgments are made to the dol TS of the Petroleum Research Fund, administered by the. merican Chemical Society, and to the Materials Resea ch Center, University of North Carolina, under Grant CH 33(;32 for support of this research.
Contribution No. 2191 from the Department of Chemistry, Indiana University, Bloomington, Indiana 47401
Preparation and Properties of Nonaborane( 13) Carbonyl' Riley Schaeffer* and Eberhard Walter
(2,2'-bipy)(CO),Mo-SnC12CH,
(h5-C,H,)Rh(CO),
(CO)ClIr(SnC14), 408 13-53-4;(PPh3)2(CO)C11r(SnC14), 393 105 - 5 ; (PPh3)2(CO)C11r(CH3SnC13), 393 10-36-6;IrCl(SnC1,)'O)(PPh3), 40903- 18-2; (PPh3)2(C0)Cl2Ir(HgCl), 145 15-76-
-+
+
(8)
most reactions, either the donor-adduct or the oxidized form is favored energetically, and a single product is obtained. In net oxidation reactions, it appears that either step can be rate The case reported here is unusual in that donor-adduct and oxidative addition isomers appear to be in measurable equilibrium both in solution and in the solid state. The energetics relating the two isomers are clearly closely balanced, as evidenced by the solvent dependence of the equilibrium. A closely related isomerism may exist in complexes like (bipy)(CO),Mo(SnCl,), where the likely isomers are chloride bridged, previously shown, and nonbridged (bipy)(CO),ClMo(SnCl,) oxidative elimination product^.'^>^^ The existence of rapidly equilibrating intramolecular redox isomers in (PPh3)2(CO)ClIr(SnC14)may have important implications for the formulation of the products of reactions between metal complexes and HgX2 and SnX4 and for an understanding of the factors important in the microscopic reverse of oxidative addition, reductive elimination. Registry No. tran~-IrCl(CO)(PPh3)~, 15318-31-7;(PPh3)*(16) J. C. B. Dammann, Ph.D. Thesis, University of North Carolina, Chapel Hill, N. C., 1972. (17) T. R. Durkin and E. P. Schram, Inorg. Chem., 11, 1054 ( 197 2). (1 8) I. N. Nowell and D. R. Russell, Chem. Commun., 8 17 (1967). (19) M. Elder and D. Hall, Inorg. Chem., 8 , 1268 (1969). (20) J. W. McDonald and F. Basolo, Inorg. Chem., 10,492 (1971). (21) R. T. Jernigan and C. R. Dobson, Inorg. Chem., 11, 81 (1972). (22) K. Edgar, B. F. G. Johnson, J . Lewis, and S. B. Wild, J. Chem. S o c . , S e c t . A , 2851 (1968). (23) B. Demerseman, G. Bouquet, and M. Bigorgne, J . Ovganometal. Chem., 35, 341 (1972). (24) A. J. Oliver and W. A. G. Graham, Znorg. Chem., 10, l(1971). (25) J. F. Harrod, C. A. Smith, and K. A. Than, J. A m e r . Chem. SOC.,94, 8321 (1972).
Received February 20, 1973
In the thermal decomposition of borane carbonyls such as BH3C0 and B4HsC0, carbon monoxide and the parent borane fragments are formed Carbon monoxide is a weak nucleophile and has little effect on subsequent reactions. This fact makes borane carbonyls useful precursors to study the chemistry of reactive borane fragments such as ligand exchange reactions, hydrogenation, and hydroboration.'-13 In addition, they may be precursors of some less stable boranes. As a promising source of a B9H,, fragment we wish to report the preparation of B9H13C0. This compound is formed when iaB9H15 is decomposed a t -30" in pentane solution under 25 atm of CO. In a typical reaction i-B9H15 was prepared by refluxing 2.26 g of KB9H14 with liquid hydrogen chloride in a 200-ml heavy-walled flask equipped with a break-off tip.'4i15 Unreacted hydrogen chloride was distilled from the flask at -78" and the last traces were pumped off under high vacuum. Dried Iz-pentane, 100 ml, and about a tenfold excess of CO were condensed into the reaction flask at -196". The amount of CO was controlled such that 30 atm of pressure would not be exceeded if the sample was accidently warmed to room temperature. The (1) Studies of Boranes. X X X V I . For paper X X X V of this series, see R. R . Rietz and R. Schaeffer, J . Amer. Chem. SOC., 95, 4580 (1973). ( 2 ) A. B. Burg,J . Amer. Chem. Soc., 74, 3482 (1952). (3) G. L. Brennan and R. Schaeffer, J . Inorg. Nucl. Chem., 15, 205 (1960); 2 0 . 310 (1961). (4) Y . C. Fu and G. R. Hill, J . Amer. Chem. SOC.,84, 353 (1962). (5) M. E. Garabedian and S. W. Benson, J. Amer. Chem. SOC.,86, 176 (1964). (6) T. P. Fehlner and W. S. Koski, J. A m e r . Chem. S O C . ,87, 409 (1965). (7) R. E. Hollins and F. E. Stafford, Inorg. Chem., 9, 877 (1970). ( 8 ) G. T. TerHaar, Sr. M. A. Fleming, and R. W. Parry, J . Amer. Chem. Soc., 84, 1767 (1962). (9) J. R. Spielrnan and A. B. Burg, Inorg. C h e m . , 2 , 1139 (1963). (10) J. C. Carter and R. W. Parry, J. A m e r . Chem. SOC.,87, 2354 (1965). (11) J . Grotewold, E. A. Lissi, and A. E. Villa, J . Chem. SOC.A , 8, 1034 (1966). (12) A. D. Norman and R. Schaeffer, J. A m e r . Chem. SOC.,88, 1143 (1966). (13) K. F. Hoffman and U. Engelhardt, Z . Naturforsch., E , 25, 317 (1970). (14) J. Dobson, P. C. Keller, and R. Schaeffer, J. Amer. Chem. SOC., 87, 3522 (1965). (15) J. Dobson, P. C. Keller, and R. Schaeffer, Inorg. Chem., 7, 399 (1968).
2210 Inorganic Chemistry, Vol. 12,No. 9, 1973
Notes
Table 1. Partial Mass Spectrum of B,H,,CO at 70 eV ("B,H,;CO = 140 mass units)
65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94
2.0 6.6 6.6 7.6 6.6 3.0 3.0 2.0
